Survey finds Kirtland's Warbler population stable
After it was delayed for a year, this summer state and federal agencies and volunteers counted the population of the rare songbird, the Kirtland’s warbler.
A full survey is conducted every five years, but the COVID pandemic delayed counting the Kirtland's Warbler until this summer.
An estimated total of 2,245 pairs of the rare songbird were counted.
“It's good news because the population is holding steady. Remember, it was only 1987 when the population was below 200 pairs. The goal for the population was 1,000 pairs and we've just blown right past that now,” said William Rapai, the executive director of the Kirtland’s Warbler Alliance, one of the organizations working to conserve habitat for the songbird.
He says that’s about the same population as counted in 2015.
According to a release by the U.S. Forest Service, researchers survey nesting areas, listening for singing males advertising and defending nesting territories. Federal and state agencies and “droves” of volunteers partner to count the population.
It’s taken decades of habitat restoration for the Kirtland’s warbler to recover. The songbird was removed from the federal list of endangered species in the fall of 2019.
The bird depends on the disruption of jack pine forests. Wildfires used to burn down the trees and the warbler nested in young jack pines. Now the trees are cut and new jack pines planted for Kirtland’s warblers’ habitat.
Another aspect of helping the warbler return was managing brown-headed cowbirds. Those birds are parasites that lay their eggs in the nests of Kirtland’s warblers and other bird species. The U.S. Forest Service reports the larger cowbird chicks out-compete warbler chicks for food which causes them to die, while the warbler parents unknowingly raise the cowbird chicks.
Most of the birds were counted in the northern lower peninsula of Michigan, mostly in the Huron and Manistee National Forests, but a few were counted in the upper peninsula, Wisconsin, and Ontario.